1. Field of the Invention
The present invention relates to a living tissue harvesting apparatus which harvests living tissues, for example, subcutaneous blood vessels such as a great saphenous vein under observation of an endoscope, particularly to an improvement of a holder assembled in this living tissue harvesting apparatus.
2. Description of the Related Art
A cannula and surgical method for use in drawing and harvesting subcutaneous blood vessels such as a great saphenous vein in an endoscopic manner are known, for example, by PCT/US99/31242 and Jpn. Pat. Appln. KOKAI Publication No. 2000-37389.
The cannula is a straight tubular member which has a device inserting path inside, and includes an operation portion in a proximal end. Through the device inserting path of the cannula, from an operation portion side, a traction portion, rigid endoscope, and incision forceps are detachably inserted. The traction portion includes a loop portion projecting from a tip end of the cannula and having an angle with respect to an axial direction of the cannula in a distal end.
When the cannula is used to harvest the subcutaneous blood vessels such as the great saphenous vein in the endoscopic manner, the following surgical method is used. That is, as shown in FIG. 73, a reference numeral 100 denotes a leg. To harvest a harvesting object blood vessel (hereinafter referred to as the blood vessel) C such as the great saphenous vein which extends over the whole length to an ankle B from an upper part of an inguinal portion A of a femoral region, a cut skin portion E1, E2, or E3 is made by a scalpel, for example, in any one portion of an upper portion of the inguinal portion A, knee D, and ankle B immediately above the blood vessel C.
Subsequently, the blood vessel C is exposed in a position of each cut skin portion E1, E3, or E3 by a dissector. Furthermore, a tissue right above the blood vessel C is exfoliated by the similar dissector with respect to a distance from each cut skin portion E1, E2, or E3, which can be observed with the naked eye.
FIG. 74 is a sectional view taken along line 74—74 of FIG. 73, reference numeral 101 denotes a scurf skin, 102 denotes a subcutaneous tissue, 103 denotes a connective tissue on the blood vessel, and the blood vessel C exists under the connective tissue on the blood vessel 103. First, a cannula including a conical chip on the tip end of the cannula is used as the dissector to strip the blood vessel C and peripheral tissue and to form a cavity G. Here, the harvesting of the blood vessel C extending toward the inguinal portion A through the cut skin portion E2 of the knee D will be described. The harvesting comprises: removing the conical chip from the cannula tip end; inserting the cannula into the cavity G from the cut skin portion E2; and inserting the cannula toward the cut skin portion E1 of the knee D along the upper portion of the blood vessel C during observation with the rigid endoscope.
In the process of the inserting of the cannula into the cavity G, an operation comprises: operating the operation portion in the proximal end of the cannula to move the traction portion forwards/backwards; holding the blood vessel C with the loop portion in the distal end to strip the vessel from the subcutaneous tissue 102 and connective tissue on the blood vessel 103; and cutting a plurality of side branches F branched from the middle of the blood vessel C by the incision forceps. This operation is repeated to harvest the blood vessel C between the cut skin portion E2 and inguinal portion A.
Moreover, in the great saphenous vein extraction system, the blood vessel C has to be prevented from being damaged when the side branches F are cut from the blood vessel C to be extracted. To safely cut the branches it is important to operate the blood vessel C by the traction portion in an arbitrary direction and to hold the vessel at a distance from incision forceps. When the blood vessel C is operated and held by the traction portion in this manner, tension is applied to the side branches F to be cut. Therefore, the side branches F can clearly be identified, and the side branches F can be cut without damaging the blood vessel C.
However, in the related-art manual operation, when the blood vessel C is held and pressed by the traction portion, a hand side of root portions of the side branches F is pressed with respect to the view field in accordance with a shape of the traction portion. Therefore, when the blood vessel C is pushed in a front surface direction of the view field in this state, the blood vessel C is bent, and rises on the back side of the side branch F. At this time, the incision forceps are projected forwards to cut the side branches F, and the blood vessel C which has risen may be damaged by mistake.
When the traction portion for holding the blood vessel C exists before the side branch F in this manner, the portion obstructs the front observation view field, and the positional states of the side branches F and blood vessel C cannot satisfactorily be confirmed. Therefore, also in this case, the blood vessel C may be damaged by mistake.
Since all the side branches F branched from the blood vessel C are searched under the endoscope and cut one by one in the above-described great saphenous vein extraction system, it takes considerable time to extract the blood vessel C. Moreover, to cut the side branches F, the side branches F cannot be held by the loop portion. Therefore, there is possibility that the treatment is performed in the unstable state. In this case, the blood vessel C may be damaged.